In the prior art, transducer mounting structures are disclosed which comprise different types of arrangements of electrically-driven actuators. The arrangements of these actuators are dictated by the functions of different transducer mounting designs and control procedures.
An example of a prior art transducer mounting structure is disclosed by U.S. Pat. No. 8,919,631 entitled “Wire Bonder Including a Transducer, a Bond Head, and a Mounting Apparatus”. The patent discloses an apparatus for mounting a transducer to a bond head of a wire bonder, wherein the bond head of the wire bonder is operative to mechanically drive the transducer when forming electrical interconnections between separate locations within a semiconductor package. Specifically, the apparatus comprises a flexural structure having a connector for connecting to the transducer, the flexural structure being configured to bend, and actuators attached to the flexural structure. The actuators are operative to bend the flexural structure to thereby cause a displacement of the transducer connected thereto via the connector.
In the aforesaid transducer mounting structure, the ultrasonic vibration of the transducer will be influenced by the oscillation of their electrically-driven actuators since the actuators are fixed directly to the transducer. For instance, if the transducer assembly is fixed to the actuators vertically, this will generate relatively large vertical vibrations, which has the effect of damaging the surface of a die being bonded and thereby affect the bonding quality, especially for sensitive electronic devices.
There is no specific clamping portion configured on the aforesaid transducer to securely fix the actuators. Since the oscillatory stroke of most actuators such as piezoelectric actuators are only several microns in length, this stroke is typically magnified by the oscillating mounting structure to thereby increase the amplitude of vibration at a capillary near a tip of the transducer. If the clamping of the actuators is not secure enough, the strokes transmitted from the actuators to the mounting structure may be weakened, and in turn significantly affect the amplitude of vibration at the capillary. Moreover, if only epoxy is used to glue the actuators onto a support portion of the transducer, the epoxy would not only absorb the stroke of the actuator, but would also generate a gap between the actuators and their support portion during extension or contraction. This gap that is created may alter the positions of the actuators, and may even cause them to be dislodged from the support portion.